JP2014144903A - Diamond production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of synthesizing, from an organic explosive agent, diamond having a relatively large number of hydrophilic functional groups on the surface, by using a simple device in a simple and efficient manner and with high yield.SOLUTION: A diamond production method is characterized in that a container or bag full of inert gas is filled with an explosive agent, the container is put in a pressure-resistant container, and the explosive agent is exploded in the pressure-resistant container.

Description

  The present invention relates to a method for producing diamond that can easily and efficiently produce diamond directly from carbon atoms in the explosive by detonating the explosive using a simple device.

  Conventionally, explosive explosions generate high-temperature and high-pressure conditions of 3000 to 5000 ° C. and several hundreds of thousands of atmospheres, recover the products obtained by the explosion, separate foreign substances, and chemistry with nitric acid, sulfuric acid, etc. There is known a method of synthesizing diamond fine particles from explosive-derived carbon by treating and purifying in an automated manner. The primary particle size of the diamond is nanometer size, and is used for precision abrasives, lubricants, lubricants, reinforcing agents, coating agents, and the like.

  As a method for synthesizing the nano-sized diamond, (a) a pressure vessel is filled with an inert gas with respect to carbon atoms in the explosive, and the explosive is exploded therein (air-cooled explosive method); (B) There is a synthesis method (water-cooled explosion method) in which an explosive is exploded in water (for example, refer to Non-Patent Document 1, page 342, right column, lines 5 to 9 and Table 3).

The diamond obtained by the air-cooled explosion method has a smaller primary particle (that is, the specific surface area of the particle is larger) than that obtained by the water-cooled explosion method, and a hydrophilic functional group (—COOH group, -OH group, -NH ₂ group, -NH group) has characteristics such often (see page 13 of non-Patent Document 2). As described above, since the diamond obtained by the air-cooled explosion method has many hydrophilic functional groups such as —COOH and —OH, the surface thereof has various molecules and atoms (for example, fluorine atoms, fluorine atom-containing compounds). , A silicon compound).

  However, in the case of air-cooled explosion using an inert gas, it is necessary to use a large amount of inert gas having a cooling effect in order to cool the explosive explosion products. It is necessary to increase the pressure in the pressure vessel at the time of explosion. In the blasting method, the yield of diamond is usually increased by continuously repeating explosions in a pressure-resistant vessel. However, in the case of air-cooled bombardment, an inert gas is used in the pressure-resistant vessel before the explosion. Since it is necessary to make it satisfy | filled, if a container is enlarged or the inside of a pressure vessel is made into a high voltage | pressure, work efficiency will fall large.

  Therefore, it is hoped to develop an air-cooled explosion method that produces diamond that can be easily surface-modified with a relatively large number of hydrophilic functional groups on the surface in a simple and efficient manner with high yield. It is rare.

V Yu Dolmatov, “Detonation-synthesis nanodiamonds: synthesis, structure, properties and applications,“ Russian Chemical Reviews 76 (4), pp. 339-360 (2007) Valery Dolmatov, “Aboutness of Creation of Large-Scale Modern Production of Denominations,” Rusnanotech, 2010

  Therefore, the object of the present invention is to provide a method for synthesizing diamond having a relatively large number of hydrophilic functional groups on the surface from an organic explosive using a simple apparatus in a simple, efficient and high yield. There is to do.

  As a result of diligent research in view of the above-mentioned object, the present inventors filled an explosive into a container or bag filled with an inert gas in an air-cooled explosion method for synthesizing diamond, and filled the container or bag. The present inventors have found that diamonds having a large number of hydrophilic functional groups on the surface can be synthesized with high efficiency and high yield by detonating the explosives in a pressure-resistant container.

  That is, in the method for producing diamond of the present invention, an explosive is filled in a container or bag filled with an inert gas, and the explosive filled in the container or bag filled with the inert gas is placed in a pressure-resistant container. It is installed and detonated.

  The step of placing the explosive filled in the inert gas-filled container or bag in the pressure-resistant container and exploding is preferably repeated twice or more continuously.

  After detonating the explosive, it is preferable to have a step of washing the inner wall of the pressure-resistant container with water and recovering the synthesized diamond.

  Oxygen may be added in an amount of 0 to 1% by volume to the inert gas.

  The explosive is preferably a mixture of trinitrotoluene and cyclotrimethylenetrinitroamine, or a mixture of trinitrotoluene and tetramethylenetetranitramine.

  The oxygen balance of the explosive is preferably negative.

  The inert gas is preferably nitrogen, argon, carbon dioxide or helium.

  It is preferable to explode while cooling the pressure-resistant container.

The pressure resistant container preferably has a volume of 5 to 500 m ³ with respect to 1 kg of the explosive.

  A leak valve or Laval nozzle is provided in the pressure-resistant container, a pressure-resistant sealed container is further provided downstream of the leak valve or Laval nozzle, and the pressure generated by the explosion is supplied to the sealed container via the leak valve or Laval nozzle. It is preferable to open it.

  The method of the present invention is characterized in that an explosive is filled in a container or bag filled with an inert gas, and then explodes in a pressure resistant container. By the method of the present invention, the inside of the pressure resistant container is filled with an inert gas. Since replacement work can be omitted as much as possible, even if explosions are repeated continuously, work efficiency does not decrease, and diamond can be synthesized in a high yield.

It is a schematic cross section which shows an example of the apparatus used with the manufacturing method of the diamond of this invention. It is a schematic diagram which shows the example of the container used with the manufacturing method of the diamond of this invention. It is a schematic cross section which shows another example of the apparatus used with the manufacturing method of the diamond of this invention. It is a schematic diagram which shows the container for filling with the explosive used in Example 1, and nitrogen. 6 is a schematic diagram showing an ice container used in Comparative Example 2. FIG.

[1] Diamond production method Preferred embodiments of the diamond production method of the present invention will be described in detail, but the present invention is not limited thereto.

(1) Synthesis of diamond The diamond production method of the present invention is an air-cooled explosion method in which a container filled with an explosive is filled with an inert gas, the container is installed in a pressure-resistant container, and the explosive is exploded. Is the law. As the explosive, an organic explosive is used. The container for filling the explosive may be of any material and structure as long as it can be sealed to the extent that it can maintain a state filled with an inert gas, but it is destroyed when the explosive is exploded. Preferably, it is of a material or structure.

  As shown in FIG. 1, the explosive 3 is hung and installed in a pressure resistant container 1 with a suspension member 4 in a state where the container 2 is filled with an inert gas. The position of the suspension is appropriately adjusted according to the shape of the container, the type and amount of the explosive, etc., so that the yield of the diamond obtained is as high as possible. In the case of a spherical pressure-resistant container 1 as shown in FIG. 1, it is preferable to suspend the pressure-resistant container 1 so as to be positioned substantially at the center. By using a metal wire such as a copper wire as the suspension member 4, it can be used as a conducting wire for supplying a current to the electric detonator attached to the explosive.

  By filling the explosive 3 in the container 2 filled with an inert gas and causing it to explode, the pressure generated during the explosion can be effectively increased, and the periphery of the explosive 3 is filled with the inert gas. The oxidation of the diamond to be purified is effectively suppressed. The inert gas used is preferably inert to carbon atoms, and gases such as nitrogen, argon, carbon dioxide, and helium are preferred. The pressure of the inert gas filling the container may be normal pressure, but may be higher than normal pressure. From the viewpoint of increasing the amount of hydrophilic functional groups present on the diamond surface, depending on the conditions such as the type of explosive used and the shape of the pressure-resistant container, the oxygen concentration in the container 2 is 1 It may be preferable to contain a trace amount in the range of not more than volume%.

  Diamond generated from carbon derived from the organic explosive is easily cooled to room temperature from a high temperature state after explosion when the cooling speed is low from about 1200 ° C. to room temperature. To phase change. Therefore, in order to suppress the phase transition and increase the purity and yield of diamond, it is preferable to cool the pressure-resistant container promptly. The pressure-resistant container can be cooled by natural cooling, but in order to cool more efficiently, the pressure-resistant container itself is cooled from the surroundings by, for example, sending air to the outer wall of the pressure-resistant container. Is preferred.

  The product obtained by the explosion is recovered as an aqueous dispersion by washing the inner wall of the pressure-resistant container 1 with water. The product may be recovered after performing one explosion, but it is more efficient to collect the products after performing two or more explosions in succession. Thus, by repeating the explosion twice or more continuously, the workability is improved and the yield of diamond is improved. When explosions are carried out twice or more in succession, oxygen in the pressure-resistant container is consumed by the first explosion, so that the effect of suppressing the oxidation of diamond in the second and subsequent explosions is also obtained.

  When two or more explosions are carried out in succession, after the first explosion, the pressure-resistant container is cooled, the explosive 3 filled in the container 2 filled with inert gas is newly installed, and the second and subsequent explosions To implement. At this time, the explosive 3 filled in the container 2 filled with the inert gas is prepared in advance for the number of explosions, and the explosion and cooling are repeatedly performed. Thus, by preparing the explosive 3 filled in the container 2 filled with the inert gas in advance and performing the air-cooled explosion method, the upper lid 7 of the pressure-resistant container 1 is opened for the second and subsequent explosions. Even if outside air (oxygen) is mixed in the pressure-resistant container 1 when charging the explosive, since the inert gas filled in the container 2 exists around the explosive 3, the influence of the increase in oxygen concentration due to the outside air mixing, That is, the oxidation of the generated diamond can be made extremely small, and as a result, the yield of diamond is improved.

  A gas provided in the pressure-resistant container 1 in order to minimize the amount of air flowing into the pressure-resistant container 1 when the upper lid 7 of the pressure-resistant container 1 is released in order to install a new explosive 3 in the pressure-resistant container 1. The installation work of the explosive 3 may be performed in a state where an inert gas is allowed to flow into the pressure-resistant container 1 from an inflow port (not shown) and the pressure-resistant container 1 is at a pressure higher than atmospheric pressure. However, it is necessary to allow a small amount of inert gas to flow in so that the generated diamond powder does not scatter.

  The container 2 for filling the explosive 3 is preferably made of a material and a structure capable of maintaining a state filled with an inert gas as described above. Examples of the material include resin, metal, glass, ceramic, and the like. From the viewpoint of easy separation when the produced diamond is recovered, resin or metal is preferable. The resin is not particularly limited, and any resin can be used widely, but polyethylene, polypropylene, PET, and the like are preferable. A metal such as aluminum, stainless steel, copper, or gold can be used. The structure preferably has a wall thickness and / or shape that can be easily broken. For example, as shown in FIG. 2, a box shape (FIG. 2A), a capsule shape (FIG. 2 ( b)), a bag shape (FIG. 2C) and the like are preferable. The size of the container is not particularly limited as long as it is easy to handle during work.

  The inside of the pressure-resistant container is preferably in a state not containing oxygen or a state containing a small amount of oxygen (1% by volume or less). For this purpose, it is preferable to perform the first explosion in a state where the air inside the pressure-resistant container is previously replaced with the above-described inert gas. When filling with an inert gas, the oxygen content is preferably 10% by volume or less, more preferably 5% by volume or less, and most preferably 1% by volume or less. As described above, when the explosion is continuously performed a plurality of times, the replacement with the inert gas may be performed at the second and subsequent explosions. However, when the explosion is performed by the method of the present invention, no explosive is used. Since the container filled with the active gas is filled, the replacement of the inert gas for the second and subsequent times may be omitted.

The pressure resistant container preferably has a volume of 5 to 500 m ³ with respect to 1 kg of the explosive. If it is smaller than 5 m ³ , it may be difficult to efficiently dissipate heat because it becomes too hot and high pressure at the time of explosion, and if it exceeds 500 m ³ , it takes time and effort to recover the product from the explosion and the yield decreases. To do.

  In order to cool the pressure-resistant container more efficiently and recover the explosion products efficiently, as shown in FIG. 3, the pressure-resistant container 1 is provided with a leak valve 5 (or a Laval nozzle), and further, the leak valve 5 (or Laval nozzle) is provided with a pressure-resistant sealed container 6, and the pressure generated by the explosion is released to the sealed container 6 via the leak valve 5 (or Laval nozzle). preferable. By increasing the cooling rate in such a configuration, the yield of diamond is improved. The pressure-resistant sealed container 6 preferably has a capacity 1 to 30 times that of the pressure-resistant container 1, more preferably 2 to 20 times the capacity, and 3 to 15 times the capacity. Most preferably.

  In the present invention, known organic explosives known as high performance explosives can be used. Organic explosives include trinitrotoluene (TNT), trinitrobenzene (TNB), trimethylenetrinitramine (RDX), tetramethylenetetranitramine (HMX), tetranitromethylaniline (tetolyl), triaminotrinitrobenzene (TATB) ), Diaminotrinitrobenzene (DATB), hexanitrostilbene (HNS), hexanitroazobenzene (HNAB), hexanitrodiphenylamine (HNDP), picric acid, ammonium picrate, benzotriazole (TACOT), ethylenedinitramine (EDNA) , Nitroguanidine (NQ), pentaerythritol tetranitrate (pen slit), benzotrifluoroxane (BTF) and the like, and these are used alone or in combination. In particular, it is preferable to use Composition B which is a mixed explosive of RDX (60%) and TNT (40%), octol which is a mixed explosive of HMX (75%) and TNT (25%), and the like.

  These organic explosives have a carbon atom content of 15% by mass or more, preferably 20 to 35% by mass, a density of 1.5 g / cc or more, preferably 1.6 g / cc or more, an explosion speed of 7000 m / s or more, Preferably it is 7500 m / s or more, oxygen balance is negative, preferably -0.2 to -0.6, detonation pressure is 18 GPa or more, preferably 20 to 30 GPa, detonation temperature is 3000 K or more, preferably It is 3000-4000K. Therefore, carbon atoms in the explosive can be efficiently converted to diamond, and since the oxygen balance is negative, diamond is not oxidized during the explosion and the yield is not reduced.

  When composition B, which is a mixture of RDX and TNT, is used as the organic explosive, it can be molded into a desired shape by melting. When using an explosive in the form of a powder (for example, having an average particle size of about 100 μm) as an organic explosive, it can be used by molding it into a predetermined shape by using it together with an organic binder such as a polymer. Is preferred. As the organic binder, a polymer material such as polybutadiene (polybutadiene), polyurethane (polyurethane), polyether (polyethylene glycol), etc., known as a binder component of a composite propellant may be used. Glycidyl azide polymer (GAP), polynitratomethylmethyl octacene, polyglycidyl nitrate, etc., which are known as polymers having high combustion heat, or wax may be used. The ratio of the organic binder is preferably 1 to 40% by mass, and the ratio of the powdered organic explosive is preferably about 60 to 99% by mass.

(2) Purification of explosive product The recovered explosive product has a core / shell structure in which the surface of a nano-order diamond is covered with graphite-based carbon, and is colored black. This unpurified nanodiamond has a density of about 2.4 to 2.6 g / cm ³ and a median diameter (dynamic light scattering method) of about 50 to 500 nm. By oxidizing this unpurified diamond by the method described later, the graphite carbon shell layer can be removed to obtain nanodiamond particles. The diamond particles purified by the oxidation treatment are secondary particles having a median diameter of about 5 to 250 nm composed of primary particles of about 2 to 10 nm.

  As an oxidation treatment method of unpurified nanodiamond, (a) a method of high-temperature and high-pressure treatment in the presence of nitric acid or the like (oxidation treatment A), and (b) a method of treatment in a supercritical fluid comprising water and / or alcohol (Oxidation treatment B), (c) A method in which oxygen is allowed to coexist in a solvent comprising water and / or alcohol, and the treatment is performed at a temperature not lower than the normal boiling point of the solvent and a pressure not lower than 0.1 MPa (gauge pressure). C) or (d) A method of treating with a gas containing oxygen at 380 to 450 ° C. (oxidation treatment D). These oxidation treatments may be performed alone or in combination. When combining the oxidation treatment, it is preferable that the unpurified nanodiamond obtained by the explosion method is first subjected to the oxidation treatment A and further subjected to any of the oxidation treatments B to C.

  Oxidation treatment A is applied to unpurified diamond obtained by the explosion method to obtain diamond particles from which a part of the graphite phase has been removed (graphite-diamond particles). The graphite layer can be further removed by performing any of the treatments of C.

The density of the oxidized diamond is determined by the amount of diamond and graphite in the diamond particles. That is, the density of diamond particles can be adjusted by changing the amount of diamond and graphite in the diamond particles according to the degree of oxidation treatment performed on the unpurified nanodiamond. (Density of Graphite: 2.25g / cm ³⁾ graphitic carbon approaches the density of the remaining amount is small, the more an Diamond (3.50g / cm ^3). Therefore, the higher the degree of purification and the smaller the residual amount of graphite carbon, the higher the density.

  The present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

Example 1
(1) Explosive preparation F
As shown in FIG. 4 (a), 0.65 kg of explosive 3 containing TNT (trinitrotoluene) and RDX (cyclotrimethylenetrinitroamine) at a ratio of 60/40 is placed in a cylindrical PET container 20a. The container 20a was sealed with a lid 20b made of PET. The operation of sucking air in the container 20a from the nozzle 21 provided on the lid 20b and filling with nitrogen gas instead was repeated five times, and then the nozzle was closed to seal the container 20a. By such an operation, the container 20a was filled with nitrogen gas, and the oxygen concentration at this time was 0.5% by volume. The explosive 3 was equipped with a detonation explosive and an electric detonator.

(2) Installation of explosive The container 20a filled with the explosive 3 is suspended by a suspension material 4 at a substantially central portion in the pressure resistant container 1 having a size of 5 m ³ as shown in FIG. The air inside was replaced with nitrogen. A copper wire was used as the suspension member 4, and the current to the electric detonator for detonating the explosive 3 was supplied through this copper wire. The pressure-resistant container 1 at this time was 1 atm, and the oxygen concentration was 4% by volume.

(3) Explosion Explosive 3 filled in container 20a filled with nitrogen gas was exploded while applying air to the outer wall of pressure-resistant container 1 with a blower.

(4) Recovery of explosive products Leave for 5 minutes after the explosion, open the top lid 7 of the pressure-resistant container 1 and clean the inner wall surface of the pressure-resistant container with water (black liquid explosive product (unrefined diamond)) Was recovered. The yield of the unpurified diamond was 7.5% by mass with respect to the amount of explosive used, the density was 2.44 g / cm ³ , and the median diameter (dynamic light scattering method) was 100 nm. This unrefined diamond was estimated from the density to be composed of 85% by volume of graphite-based carbon and 15% by volume of diamond.

(5) Purification of diamond This unpurified diamond is mixed with a 60% by mass nitric acid aqueous solution and subjected to oxidative decomposition under conditions of 160 ° C, 14 atm and 20 minutes, and then at 130 ° C, 13 atm and 1 hour. Oxidative etching treatment was performed. Particles from which graphite was partially removed were obtained by the oxidative etching treatment. The particles were refluxed with ammonia at 210 ° C., 20 atm for 20 minutes, neutralized, then naturally settled, washed with 35 mass% nitric acid by decantation, and further washed with water three times by decantation. It was dehydrated by centrifugation and dried by heating at 120 ° C. to obtain a diamond powder. The yield of this diamond powder was 4.1% by mass with respect to the amount of explosive used, the density was 3.36 g / cm ³ , and the median diameter was 35 nm (dynamic light scattering method). Calculated from the density, it was estimated to be composed of 89% by volume of diamond and 11% by volume of graphite-based carbon.

Example 2
In the same manner as in Example 1, (1) Preparation of explosives, (2) Installation of explosives, and (3) Explosive operation, (1) Preparation of explosives, (2) Installation of explosives, And (3) The explosion operation was repeated four times, followed by a total of five explosions. However, in the second and subsequent explosions, the operation of replacing the gas in the container with nitrogen after installing the explosive was omitted. After the fifth explosion, (4) explosive product recovery work and (5) diamond purification were performed in the same manner as in Example 1. The yield of the obtained diamond powder was 4.3% by mass with respect to the amount of explosive used, the density was 3.38 g / cm ³ , and the median diameter was 20 nm (dynamic light scattering method). Calculated from the density, it was estimated to be composed of 90% by volume of diamond and 10% by volume of graphite-based carbon.

Comparative Example 1
(1) Preparation of explosive As shown in FIG. 5, the explosive 3 used in Example 1 is filled in an ice container 22a formed by freezing degassed water (FIG. 5 (a) and FIG. 5 ( b)), which was covered with an ice container 22b formed by freezing degassed water (FIG. 5 (c)). The explosive 3 was equipped with a detonation explosive and an electric detonator. The weight of ice was 13 kg in total for the containers 5a and 5b.

(2) Installation of explosives As shown in FIG. 1, the ice containers 22a and 22b filled with the explosive 3 are suspended by a suspension material 4 at a substantially central portion in a pressure-resistant container 1 having a size of 3 m ³ . The air in the pressure resistant container 1 was replaced with nitrogen. A copper wire was used as the suspension member 4, and the current to the electric detonator for initiating the explosive was supplied through the copper wire. The pressure-resistant container 1 at this time was 1 atm, and the oxygen concentration was 4% by volume.

(3) Explosion Explosive 3 filled in ice containers 22a and 22b was exploded while applying shower-like water to the entire inner wall of pressure-resistant container 1 at a supply rate of 60 kg / min.

(4) Recovery of explosion product After leaving the explosion, leave it for 5 minutes, open the top lid 7 of the pressure-resistant container 1 and clean the inner wall surface of the pressure-resistant container with water. ) Was recovered. The yield of this unpurified nanodiamond was 10.2 mass% with respect to the amount of explosive used, the density was 2.55 g / cm ³ , and the median diameter (dynamic light scattering method) was 230 nm. This unpurified nanodiamond was estimated to be composed of 76% by volume of graphitic carbon and 24% by volume of diamond, as calculated from the density.

(5) Purification of diamond The unpurified diamond was purified in the same manner as in Example 1 to obtain diamond powder. The yield of the diamond powder was 6.0% by mass with respect to the amount of explosive used, the density was 3.38 g / cm ³ , and the median diameter was 130 nm (dynamic light scattering method). Calculated from the density, it was estimated to be composed of 90% by volume of diamond and 10% by volume of graphite-based carbon.

XPS analysis of the hydrophilic functional groups (—COOH group, —OH group, —NH ₂ group and —NH group) present on the surface of the diamond obtained in Examples 1 and 2 and Comparative Example 1 by the gas phase chemical modification method Quantified by Quantification of -COOH groups is described in Y.C. Nakayama, T .; Takahagi and F.M. Soeda, J .; Polym. Sci. : Part A, performed by reference to 26,559 (1988), Determination of the -OH group, -NH ₂ group and -NH group, after quantitatively by reacting trifluoroacetic anhydride (TFAA), XPS measurements And the total amount of —OH group, —NH ₂ group and —NH group present on the diamond surface was determined from the detected F concentration. Incidentally results, -COOH group, -OH group, the total amount of the -NH ₂ group and -NH groups, indicated by a relative value obtained by Example 1 and 100.

注（１）：密度から見積もったグラファイト（Ｇ）とダイヤモンド（Ｄ）との比率
注（２）：ダイヤモンド表面の−ＣＯＯＨ基、−ＯＨ基、−ＮＨ_２基及び−ＮＨ基の合計量であり、実施例１を１００とした相対値で示した。

Note (1): Ratio of graphite (G) and diamond (D) estimated from density Note (2): Total amount of —COOH groups, —OH groups, —NH ₂ groups and —NH groups on the diamond surface In Example 1, the relative value was set to 100.

  As is clear from Table 1, the diamond produced by the air-cooled explosion method of the present invention had a smaller particle size and a larger amount of hydrophilic functional groups than the diamond produced by the water-cooled explosion method. The reason for the large amount of hydrophilic functional groups is that the diamond produced by air-cooled explosion method has a slower cooling rate and the amount of graphite is larger than diamond produced by water-cooled explosion method. This is probably because many hydrophilic functional groups were generated.

DESCRIPTION OF SYMBOLS 1 ... Pressure-resistant container 2 ... Container 3 ... Explosive 4 ... Hanging material 5 ... Leak valve 6 ... Pressure-resistant airtight container 7 ... Upper lid 20a ... Container 20b ..Lid 21 ... Nozzle 22a, 22b ... Ice container

Claims (10)

A method for producing diamond by detonating an explosive in a pressure-resistant container, the explosive being filled in a container or bag filled with an inert gas, and in the container or bag filled with the inert gas A method for producing diamond, wherein the explosive filled in is placed in the pressure-resistant container and allowed to explode. The diamond production method according to claim 1, wherein the explosive filled in the inert gas-filled container or bag is placed in the pressure-resistant container and the step of causing explosion is repeated twice or more continuously. A characteristic diamond manufacturing method. 3. The diamond manufacturing method according to claim 1, further comprising a step of washing the inner wall of the pressure-resistant container with water after the explosion of the explosive and recovering the synthesized diamond. . The diamond manufacturing method according to any one of claims 1 to 3, wherein 0 to 1% by volume of oxygen is added to the inert gas. The diamond production method according to any one of claims 1 to 4, wherein the explosive is a mixture of trinitrotoluene and cyclotrimethylenetrinitroamine, or a mixture of trinitrotoluene and tetramethylenetetranitramine. To make diamond. The diamond manufacturing method according to claim 1, wherein an oxygen balance of the explosive is negative. The diamond manufacturing method according to any one of claims 1 to 6, wherein the inert gas is nitrogen, argon, carbon dioxide, or helium. The diamond manufacturing method according to claim 1, wherein the explosion-proof container is exploded while being cooled. 9. The diamond manufacturing method according to claim 1, wherein the pressure-resistant container has a volume of 5 to 500 m ³ with respect to 1 kg of the explosive. The diamond manufacturing method according to any one of claims 1 to 9, wherein a leak valve or a Laval nozzle is provided in the pressure-resistant container, and a pressure-resistant sealed container is further provided downstream of the leak valve or Laval nozzle, and is generated by the explosion. The method for producing diamond is characterized in that the pressure is released to the sealed container through the leak valve or a Laval nozzle.

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